{{concatenate}} helper
This helper is very similar to the {{join}} helper, but it doesn't have the first param. It always returns all arguments connected into one string.
Syntax:
{{concatenate value1 value2 value3}}
Example:
{{concatenate "a=" 1 "&b=3"}}
Example output:
"a=1&b=3"
This helper is especially useful if you need to combine theme options into string:
{{getPostsByTags (concatenate "count=" @config.post.additionalParam)}}